Armed Men Take Police HQ In Eastern Ukraine City

More than a dozen armed men have seized a police station in the city of Sloviansk, near Ukraine's border with Russia. The pro-Russian group is one of several that have seized public government buildings in the past week. Ukrainian officials promise a "very tough" response.

Update at 6:00 p.m. ET: Vice President Biden Going To Kiev

The White House announced Saturday the Vice President Joe Biden will travel to Kiev, Ukraine on April 22, to talk with government leaders and members of the civil society.

According to the White House statement, Biden will consult with government officials on the international community's efforts to "help stabilize and strengthen Ukraine's economy and to assist Ukraine in moving forward on constitutional reform, decentralization, anti-corruption efforts, and free and fair presidential elections."

Update at 12:45 p.m. ET: Video Of The Takeover Is Posted

A green truck or van was used to pull security bars off the windows of the police station taken over in Sloviansk Saturday, according to people who posted a video online today. The footage was apparently shot by neighbors who noticed that a force was gathering outside the building.

The footage shows that it took several attempts to get the bars off the window — something the residents found to be a bit funny, according to the audio track. The video was posted to YouTube by EuroMaidan PR, a group that supports Ukraine's interim government.

"Masked men in mismatched camouflage clothes armed with pistols and rifles stood near the building, a Reuters witness said. They were wearing orange and black ribbons, a symbol of the Soviet victory in World War Two that has been adopted by pro-Russian separatists in Ukraine."

The news agency adds that a crowd has gathered outside the building; some of its members helped build a barricade around the police station.

Saying that a special forces unit had been dispatched to Sloviansk, Interior Minister Arsen Avakov wrote on his Facebook page today that the government's "response will be very tough because there is a difference between protesters and terrorists," according to Radio Free Europe.

Pro-Russian forces continue to occupy buildings in Donetsk and Luhansk. Ukraine's top officials have said they view such acts as terrorism; they have also sought to reassure ethnic Russians that the new government will share political power and will not ban the Russian language.

The U.S. is widening its effort to punish those it says are responsible for Crimea's secession from Ukraine, with the Treasury Department targeting seven Crimean separatists with economic sanctions.

From NPR's Scott Horsley:

"The new sanctions are authorized under an Executive Order that President Obama signed last month. It freezes assets, limits travel to the U.S., and prohibits Americans from doing business with the sanctioned individuals. All seven people targeted are, including several who were involved in what the Administration calls the "unauthorized referendum" that led Russia to annex Crimea.

"The Treasury Department is also sanctioning a natural gas company with drilling rigs off Crimea's west coast."